package deom1;

public class Test1 {
    public static void main(String[] args) {

    }
    public int tribonacci(int n) {
        if(n == 0)return 0;
        if(n == 1 || n == 2) return 1 ;
        int a = 0 ;
        int b = 1 ;
        int c = 1 ;
        int d = 0 ;
        for(int i = 3 ; i <= n ; i ++){
            d = a+b+c ;
            a = b ;
            b = c ;
            c = d ;
        }
        return d ;
    }
    
}
